Key actors of mammalian immunity originated from bacterial antiphage systems. The 出版full extent of immune system conservation between bacteria and eukaryotes is unknown. Here, we show that the silent information regulator 2 (SIR2) protein domain, present in antiphage systems, plays a role in eukaryotic innate immunity. We identified SIRal, a human protein with a SIRim domain (subtype of SIR2) that plays a pivotal role in the animal Toll-like receptor pathway of innate immunity and protects against bacterial and viral infections. Proteins containing a SIRim domain are found across 19% of eukaryotic genomes, including zebrafish, where SIRal plays a role in inflammation. This work opens up avenues of research on the immune role of eukaryotic SIRim proteins as well as on the involvement of SIRal in human pathology.
Expansion in situ genome sequencing links nuclear abnormalities to aberrant chromatin regulation
Here, we describe expansion in situ genome sequencing (ExIGS), a technology that enables sequencing of genomic DNA and super-resolution localization of nuclear proteins in single cells. Applying ExIGS to progeria-derived fibroblasts revealed that lamin abnormalities are linked to hotspots of aberrant chromatin regulation that may erode cell identity. Lamin was found to generally repress transcription, suggesting that variation in nuclear morphology may affect gene regulation across tissues and aged cells. These results demonstrate that ExIGS may serve as a generalizable platform with which to link nuclear abnormalities to gene regulation, offering insights into disease mechanisms.
The year 2023 witnessed an extraordinary surge in marine heatwaves (MHWs) across Earth’s oceans, setting new records in duration, extent, and intensity, with MHW activity totaling 53.6 billion °C days square kilometer—more than three standard deviations above the historical norm since 1982. Notable events include the North Atlantic MHW (276-year return period) and the Southwest Pacific (141 years). Using ECCO2 (Estimating the Circulation and Climate of the Ocean-Phase II) high-resolution daily data, we conducted a mixed-layer heat budget analysis and identified region-specific drivers: enhanced shortwave flux and a shallower mixed layer in the North Atlantic and North Pacific, reduced cloud cover and increased advection in the Southwest Pacific, and oceanic advections in the Tropical Eastern Pacific. The 2023 MHWs highlight the intensifying impacts of a warm climate and the challenges in understanding extreme events.
医学Medicine
Pre-European contact leprosy in the Americas and its current persistence
Here, we show that M. lepromatosis infected humans in the Americas before European contact. By screening 389 ancient and 408 contemporary samples, we have expanded the genetic data available for the species. Phylogenetic analyses revealed distinct human-infecting clades of M. lepromatosis, with one dominating North America since colonial times. The presence of millennia-old strains in North and South America indicates that M. lepromatosis may have been widespread during the Late Holocene, demonstrating that M. lepromatosis leprosy has a long-standing history in the Americas before European arrival.
生态学Ecology
Little-to-no industrial fishing occurs in fully and highly protected marine areas